Nursing Elites

1. Which gas is the most abundant in Earth's atmosphere?

• A. Nitrogen
• B. Oxygen
• C. Carbon dioxide
• D. Argon

Correct answer: A

Rationale: Nitrogen is the most abundant gas in Earth's atmosphere, constituting approximately 78% of the air we breathe. It is essential for various biological processes, including plant growth and nitrogen fixation. Moreover, nitrogen is a key component of the greenhouse effect, playing a crucial role in regulating the planet's temperature. Oxygen, while important for respiration, comprises about 21% of the atmosphere. Carbon dioxide, though vital for photosynthesis and a greenhouse gas, is present in much lower concentrations than nitrogen. Argon, an inert gas, is a minor component of the atmosphere.

2. Histamine, released during an allergic reaction, causes symptoms like:

• A. Fever and fatigue
• B. Runny nose and itchiness
• C. Muscle aches and joint pain
• D. Cough and shortness of breath

Correct answer: B

Rationale: Histamine is a chemical released by the immune system during an allergic reaction. It is responsible for causing symptoms such as a runny nose, itchiness, sneezing, and watery eyes. These symptoms are commonly seen in allergies like hay fever. Fever and fatigue (option A) are not typically caused by histamine release during an allergic reaction. Muscle aches and joint pain (option C) are not common symptoms of histamine release in allergic reactions. Cough and shortness of breath (option D) are more commonly associated with asthma or respiratory allergies rather than histamine release.

3. Which hormone is responsible for regulating the body's metabolism?

• A. Insulin
• B. Thyroxine
• C. Melatonin
• D. Adrenaline

Correct answer: B

Rationale: Thyroxine, also known as T4, is produced by the thyroid gland and plays a vital role in regulating the body's metabolism. Insulin is not responsible for regulating metabolism; instead, it helps regulate blood sugar levels. Melatonin is involved in regulating sleep-wake cycles, not metabolism. Adrenaline, also known as epinephrine, is a stress hormone that prepares the body for fight or flight responses, not primarily involved in metabolic regulation.

4. What is the significance of studying pedigrees in human genetics?

• A. Predicting the exact outcome of genetic crosses in humans.
• B. Tracing the inheritance of complex traits with multiple contributing genes.
• C. Identifying carriers of dominant genetic disorders.
• D. Determining the risk of acquiring a specific mutation de novo.

Correct answer: B

Rationale: Pedigrees are diagrams that show the relationships within a family and can be used to track the inheritance patterns of specific traits or diseases. While pedigrees can provide information on the inheritance of single gene disorders (such as identifying carriers of dominant genetic disorders, as mentioned in option C), their primary significance lies in studying complex traits with multiple contributing genes. These traits do not follow simple Mendelian inheritance patterns and are influenced by both genetic and environmental factors. By analyzing pedigrees, researchers can identify patterns of inheritance for complex traits, such as polygenic diseases or traits influenced by gene-environment interactions. Therefore, option B is the most appropriate choice as it captures the main significance of studying pedigrees in human genetics.

5. Which of the following structures acts like a funnel by delivering urine from the millions of collecting tubules to the ureters?

• A. The renal pelvis
• B. The renal cortex
• C. The renal medulla
• D. Bowman's capsule

Correct answer: A

Rationale: The correct answer is A: The renal pelvis. The renal pelvis serves as a reservoir for urine collected from the kidney's numerous collecting tubules, funneling it into the ureters for transport to the bladder. The renal cortex is the outer region of the kidney involved in filtration, while the renal medulla is the inner region responsible for concentrating urine. Bowman's capsule is part of the nephron and is involved in the initial filtration of blood in the kidney, not in funneling urine to the ureters.

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